Gripper locking and unlocking mechanism



Oct. 27, 1931. c. c. ALVORD 1,829,326

GRIPPER LOCKING AND UNLOCKING MECHANISM Filed June 15, 1929 3Sheets-Sheet 1 INVENTOR Maw Oct. 27, 1931. c. c ALVQRD 1,829,326

GRIPPER LOCKING AND UNLOCKING MECHANISM Filed June 15, 1929 3 sh et -s t2 INVENTOR MOM Oct. 27, 1931. c, c, ALVORD 1,829,326

GRIPPER LOCKING AND UNLOCKING MECHANISM Filed June 15, 1929 5Sheets-Sheet 3 Patented Oct. 27, 1931' PATENT OFFICE CHARLES CLINTONALVORD, OF WORCESTER, MASSACHUSETTS, ASSIG'NOR TO WORCES- TER LOOMWORKS, OF WORCESTER, MASSACHUSETTS GRIPPER LOCKING AND UNLOCKINGMECHANISM Application filed June 15,

This invention relates to tuft weaving looms and particularly to thattype-of carpet loom which employs a series of .grippers to transfer thepile tufts from the source of supply to the fell of the fabric. Thesource of supply may be either tuft frames or jacquard controlled yarncarriers, the former method being illustrated in the patent to ClintonAlvo-rd, No. 1,436,619.

It is the object of the present invention to provide "a gripper lockingand unlocking mechanism which will functionsatisfactorily I at therelatively higher speeds -:at which-carpet looms now run. I p v A secondobject is to provide simple and rapid means of disconnecting the motionwhenever required. A further object is to provide a mechanism of greatmechanical efliciency which will provide great gripping pressure forholding the tuft yarn with relative'low pressure on the working parts.

With the above and other objects in view my invention consists'in thearrangement and details of construction, disclosed in the drawings andspecification and then more particularly pointed out in the appendedclaims.

In the drawings Fig. 1 represents aside-elevation in cross section of myimproved mechanism taken on line- A-A- of Fig. 2.

ig. 2 is a front elevation of the same;

Fig. 3 shows the grippers at the pile-seizing position just as they havebeen locked vcastings provide bearings for the wing shaft 4 and a seatfor the rectangular gripper holding bar 5. Grippers 6 are fastened tothe bar as in common practice. The movable j aw 7 of each gripperterminates in a ballshaped end 8 whichre'stsin the pocket piece 9 stakedinto the oscillatory wing shaft 4. The wing shaft bearings on castings 3are 1929. Serial No. 371,152.

opened up as at 10 in Fig. 1 so as to permit the shaft to oscillatesufliciently to open and close the grippers.

The motion to lock and unlock the grippers originates with cam lever 11operated by cam 12 keyed to the main cam shaft 13 of the loom. Connectorl4 fastened on a stud at the end of the cam lever extends upward to onearm 15 of a bell crank lever freely rotatable on rock shaft 16 journaledin the loomsides. The other arm 17 of the bell crank lever has fulcrumedthereon pawl 18 which is allowed to drop freely into the tooth ofratchet 19 as shown in Fig. 1. 'Ratchet 19 is keyed to shaft 16 andthus, whenever cam lever 11 is forced downwardly by cam 12, the motionwill be transmitted by connector 14 to the bell crank lever and thenceby the pawl 18 and ratchet 19 tothe'shaft'16. In case it is desired atany time tointerrupt these periodical movements of shaft 16 due to therotation of the cam, I provide a flexible connection 20 fastened to pawl18 and running over pulleys or by other suitable means not shown to somelocation convenient for the weaver who can, by pulling the pawl out ofengagement with the ratchet tooth, quickly and easily interrupt thetrain of movement. Such a condition might exist when weaving headings ona rug at screw it will be seen in Fig. 1 that sufficient clearance isprovided between pawl 18 and the tooth of ratchet 19 to allow the pawlto be raisedoutof, or lowered into engagement therewith whenever the camroll of lever 11 is on the dwell of cam 12.

There is a lever 21 keyed on shaft 16 and equipped with a freely turningroll 22. Sector gear 23, freely pivoted on gripper fulcrum'shaft2, hasan extended arm 24 which is contacted and moved counterclockwise by roll22 whenever lever 21 swings upward due to a rise on cam'12. Anothersector gear 25 is keyed to wing shaft 4, the teeth of the two gearsbeing in mesh. Thus whenever the swing shaft is moved clockwise by theupward thrust of roll lever 21' the grippers will close. Collar 23aprevents endwise slippage 0 gear 23.

When the cam roll on lever 11; has been forced to its extreme downposition by rise 26. on cam 12 the grippers will be fully closed and thevarious parts will appear as in Fig.3, 7

bearing 3 being omitted for the sake of clarity. In order to retainthe'grippers-closed,

or. locked, I provide pawl lever 27 keyed to shaft'2 and equipped with apawl 28'which" can snapinto the recess back oftooth 29 on gear 23whenever the gearhas'been rotated by lever 21 to the position shownintheabove mentioned figure. The pawl is'urged into en gagement by a springnotshownx Lever 21 may now drop back to its position n Fig. '1

but the-grippers willreinain locked dueto pawl 28 contacting'tooth'29. v

After drawing off the proper lengthof pile yarn from the sourceof'supply the grippers descend, to their pile releasing position' at vthe shed asshown'in'Fig; 4L Anypf the wellknown mechanisms for'raisingand lowering the grlppers'may be employed such as the rack-and gearmotion shown in Fig. 1 of the Clinton Alvord Patent f r-1,436,619: Atthis point it willibe; noted that screw -:on lever '21 is'in positionto'abut oifset taih 31 on pawl 28 when-the small rise '32 on cam 12"con-.tacts and opera fi th cam roll? The'continued downwardrnovement ofthecarn lever forces the screw 30 smartly aga-il'ist'the offset tail31'thus throwing the pawl out of engage ment a trigger which, whenfree,rwas compelled'to slide by the bunter'as the'gri-ppers opened. Thefriction caused by such anarrangement' slows'down the openingo'f thegrippers and results in uneven pile Conditionsvaried from day todaydepending upon the amount of lubricantpresent on the con:

tacting surfaces; It-will be notedinthepresent arrangement, howeverthatjthe'opening screw 30 is not thus incontact-with'any part of themechanism'which isv rotated the-action of spring during the opening ofthe grip- 'pers. Oncethe pawl-' has'been forcedont'clear of tooth '29there, is nof drag imposed on; the a.

3 means 'operatively oscillating -said 1 trigger rapidly rotating".parts; :The: grippers continue to open until screw 35 which 'is,threaded in an offset'on extension arm 34 contacts gear p ers areopened'orclosedi- 23 as shown clearly in Fig. 1. The use of this checkscrew prevents straining of the pivoted joints of the individualgrippers through excessively wide opening such as occurs when no stop isprovided. I

' I am aware that various changes may be made inthe construction andarrangement of the parts without departing from the scope of thisinvention as expressed in'the claims. Ido not wish, therefore, to belimited to the scribed, but

What Ido claim and desire'to secure by Letters Patent of the UnitedStates is:

1. In a loom for weaving tufted fabrics, a se'riesof grippers havingmoveable jaws, a

construction I have herein shown and de- 7 shaft operativelycontactingsaid jaws to open and close them, a quick-releasable catch toretain the jaws in closed position, a gear on said shaft and mechanismadapted to engage said'gear whereby said shaft may be-operativelyoscillated, g i r a 1 i 2. Ina loom for weaving tufted fabrics, agripper fulcrum shaft, a gripper holding bar secured thereto, awing-shaft adapted to be operatively oscillated toopen and close a. setof grippers mounted on said bar, av sector gear on said wing shaft,a'mating gear loosely mounted on said fulcrum: shaftzand means toimovesaidmating gearewhereby said grip- 3. .In a loom for weaving tuftedfabrics, a

gripper fulcrum shaft, a wing shaft adapted to be op'erativelyoscillatedtolopen and close aset-of grippers, a sector gear-on said wing shaft,amating gear loosely mountedon said fulcrum shaft, means tov move saidmating .-'gea'r' to close the grippers, a check to retain the-grippersin closed-position and mecha- "nism' adapted to contact and release saidcheck said mechanism beingso arranged that no" relative motion occurs atthe point 'of contact while the grippers are opening whereby thespee'd'of opening is increased; 5 4.11m loom for weaving tufted fabrics,a

series of" grippers provided with movable jaws, an arm for closing thejaws, a catch to retain them in closedposition, a trigger shaft providedwitha leverhaving' a roller and an adjustable knock-off screw and meansto periodically oscillate said trigger shaft, said roller contactingsaid'arm' 'as'said shaft oscilllatesflto, close-the jaws and-saidscrewcontacting saidfcatch as said shaft oscillates to "qpen thefj aws]. v ja a H 5.IIIn iafl oom for'weaving tufted fabrics, a [series of; grippersprovided with "movable jaws, an arm for closing the jaws, a trigger,

a trigger shaft providedwith a lever fast thereon equipped with a rolleradapted to provide rolling contact with said" arm and shaft to efiectrolling contact between said trigger being adapted to releasably lockthe aws.

6. In a loom for Weaving tufted fabrics, a set of grippers, means toopen and close said grippers, mechanism to actuate said means and adevice interposed between said means and said mechanism comprising asingle tooth ratchet and driving pawl therefor adapted to be manuallymoved out of contact with said ratchet whereby the means to open andclose said grippers is rendered inoperative.

7. In a loom for weaving tufted fabrics, a gripper holding bar, wingshaft mechanism adapted to be actuated to close and open a set ofgrippers mounted on said bar, a releasable catch to retain the grippersin closed condition, and an oscillating lever provided with a roller andan adjusting bunter, the roller serving to efiect operative contactbetween the lever and the wing shaft mechanism to close the grippers andthe adjusting bunter contacting said catch to permit the grippers toopen. 7

In witness whereof I have hereunto set my hand this 13th day of June1929.

. CHARLES C. ALVORD.

